CVE-2026-94439
Estado: Pendiente de análisisAlta (7.5)—
Cuando un manejador de servidor HTTP envía una respuesta 2xx a una solicitud HTTP/1 CONNECT y retorna sin secuestrar la conexión, el servidor continúa indebidamente leyendo y atendiendo solicitudes de la conexión. Dado que una respuesta 2xx a un HTTP/1 CONNECT convierte la conexión en un túnel, el servidor no debería tratar la conexión como si siguiera conteniendo HTTP. El impacto de este comportamiento incorrecto se limita principalmente a un posible contrabando de solicitudes (request smuggling), en el que un proxy intermedio considera que los datos de la conexión están tunelizados y el servidor considera que son HTTP.
Traducción automática del texto original de NVD (en inglés).
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- Puntuación base: 7.5
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.32%
- Percentil entre todas las CVEs puntuadas: 23
- Fecha de la puntuación: 14/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1190Exploit Public-Facing Applicationinitial access85 % - Impacto principal
T1557Adversary-in-the-Middlecredential access · collection75 % - Impacto secundario
T1090Proxycommand and control70 %
Vulnerabilidad de servidor HTTP accesible remotamente sin autenticación (AV:N/PR:N) que permite request smuggling mediante respuesta CONNECT malformada. El smuggling de HTTP facilita suplantación (MITM) e inyección de proxies.
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
CWE
- CWE-444
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-94439",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-94439",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2026-10-09T16:45:53.919403Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.5,
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "NONE",
"privilegesRequired": "NONE",
"confidentialityImpact": "HIGH"
},
"impactScore": 3.6,
"exploitabilityScore": 3.9
}
]
},
"affected": [
{
"source": "security@golang.org",
"affectedData": [
{
"vendor": "Go standard library",
"product": "net/http",
"versions": [
{
"status": "affected",
"version": "0",
"lessThan": "1.26.9",
"versionType": "semver"
},
{
"status": "affected",
"version": "1.27.0-0",
"lessThan": "1.27.2",
"versionType": "semver"
}
],
"packageName": "net/http",
"collectionURL": "https://pkg.go.dev",
"defaultStatus": "unaffected",
"programRoutines": [
{
"name": "chunkWriter.writeHeader"
},
{
"name": "CanonicalHeaderKey"
},
{
"name": "Client.CloseIdleConnections"
},
{
"name": "Client.Do"
},
{
"name": "Client.Get"
},
{
"name": "Client.Head"
},
{
"name": "Client.Post"
},
{
"name": "Client.PostForm"
},
{
"name": "ClientConn.Close"
},
{
"name": "ClientConn.RoundTrip"
},
{
"name": "Cookie.String"
},
{
"name": "Cookie.Valid"
},
{
"name": "CrossOriginProtection.AddInsecureBypassPattern"
},
{
"name": "CrossOriginProtection.AddTrustedOrigin"
},
{
"name": "CrossOriginProtection.Check"
},
{
"name": "Dir.Open"
},
{
"name": "Error"
},
{
"name": "Get"
},
{
"name": "Handle"
},
{
"name": "HandleFunc"
},
{
"name": "HandlerFunc.ServeHTTP"
},
{
"name": "Head"
},
{
"name": "Header.Add"
},
{
"name": "Header.Del"
},
{
"name": "Header.Get"
},
{
"name": "Header.Set"
},
{
"name": "Header.Values"
},
{
"name": "Header.Write"
},
{
"name": "Header.WriteSubset"
},
{
"name": "ListenAndServe"
},
{
"name": "ListenAndServeTLS"
},
{
"name": "NewRequest"
},
{
"name": "NewRequestWithContext"
},
{
"name": "NotFound"
},
{
"name": "ParseCookie"
},
{
"name": "ParseSetCookie"
},
{
"name": "ParseTime"
},
{
"name": "Post"
},
{
"name": "PostForm"
},
{
"name": "ProxyFromEnvironment"
},
{
"name": "ReadRequest"
},
{
"name": "ReadResponse"
},
{
"name": "Redirect"
},
{
"name": "Request.AddCookie"
},
{
"name": "Request.BasicAuth"
},
{
"name": "Request.Cookie"
},
{
"name": "Request.Cookies"
},
{
"name": "Request.CookiesNamed"
},
{
"name": "Request.FormFile"
},
{
"name": "Request.FormValue"
},
{
"name": "Request.MultipartReader"
},
{
"name": "Request.ParseForm"
},
{
"name": "Request.ParseMultipartForm"
},
{
"name": "Request.PostFormValue"
},
{
"name": "Request.Referer"
},
{
"name": "Request.SetBasicAuth"
},
{
"name": "Request.UserAgent"
},
{
"name": "Request.Write"
},
{
"name": "Request.WriteProxy"
},
{
"name": "Response.Cookies"
},
{
"name": "Response.Location"
},
{
"name": "Response.Write"
},
{
"name": "ResponseController.EnableFullDuplex"
},
{
"name": "ResponseController.Flush"
},
{
"name": "ResponseController.Hijack"
},
{
"name": "ResponseController.SetReadDeadline"
},
{
"name": "ResponseController.SetWriteDeadline"
},
{
"name": "Serve"
},
{
"name": "ServeContent"
},
{
"name": "ServeFile"
},
{
"name": "ServeFileFS"
},
{
"name": "ServeMux.Handle"
},
{
"name": "ServeMux.HandleFunc"
},
{
"name": "ServeMux.ServeHTTP"
},
{
"name": "ServeTLS"
},
{
"name": "Server.Close"
},
{
"name": "Server.ListenAndServe"
},
{
"name": "Server.ListenAndServeTLS"
},
{
"name": "Server.Serve"
},
{
"name": "Server.ServeTLS"
},
{
"name": "Server.SetKeepAlivesEnabled"
},
{
"name": "Server.Shutdown"
},
{
"name": "SetCookie"
},
{
"name": "Transport.CancelRequest"
},
{
"name": "Transport.Clone"
},
{
"name": "Transport.CloseIdleConnections"
},
{
"name": "Transport.NewClientConn"
},
{
"name": "Transport.RoundTrip"
},
{
"name": "body.Close"
},
{
"name": "body.Read"
},
{
"name": "bodyEOFSignal.Close"
},
{
"name": "bodyEOFSignal.Read"
},
{
"name": "bodyLocked.Read"
},
{
"name": "bufioFlushWriter.Write"
},
{
"name": "cancelTimerBody.Close"
},
{
"name": "cancelTimerBody.Read"
},
{
"name": "checkConnErrorWriter.Write"
},
{
"name": "chunkWriter.Write"
},
{
"name": "connReader.Read"
},
{
"name": "connectMethodKey.String"
},
{
"name": "expectContinueReader.Close"
},
{
"name": "expectContinueReader.Read"
},
{
"name": "extraHeader.Write"
},
{
"name": "fileHandler.ServeHTTP"
},
{
"name": "fileTransport.RoundTrip"
},
{
"name": "globalOptionsHandler.ServeHTTP"
},
{
"name": "gzipReader.Close"
},
{
"name": "gzipReader.Read"
},
{
"name": "http1ClientConn.Close"
},
{
"name": "http1ClientConn.RoundTrip"
},
{
"name": "http2ClientConn.RoundTrip"
},
{
"name": "http2Handler.ServeHTTP"
},
{
"name": "http2ResponseWriter.Flush"
},
{
"name": "http2ResponseWriter.FlushError"
},
{
"name": "http2ResponseWriter.Push"
},
{
"name": "http2RoundTripper.RoundTrip"
},
{
"name": "http3ServerHandler.ServeHTTP"
},
{
"name": "initALPNRequest.ServeHTTP"
},
{
"name": "loggingConn.Close"
},
{
"name": "loggingConn.Read"
},
{
"name": "loggingConn.Write"
},
{
"name": "maxBytesReader.Close"
},
{
"name": "maxBytesReader.Read"
},
{
"name": "onceCloseListener.Close"
},
{
"name": "persistConn.Read"
},
{
"name": "persistConnWriter.ReadFrom"
},
{
"name": "persistConnWriter.Write"
},
{
"name": "populateResponse.Write"
},
{
"name": "populateResponse.WriteHeader"
},
{
"name": "readTrackingBody.Close"
},
{
"name": "readTrackingBody.Read"
},
{
"name": "readWriteCloserBody.CloseWrite"
},
{
"name": "readWriteCloserBody.Read"
},
{
"name": "redirectHandler.ServeHTTP"
},
{
"name": "response.Flush"
},
{
"name": "response.FlushError"
},
{
"name": "response.Hijack"
},
{
"name": "response.ReadFrom"
},
{
"name": "response.Write"
},
{
"name": "response.WriteHeader"
},
{
"name": "response.WriteString"
},
{
"name": "serverHandler.ServeHTTP"
},
{
"name": "socksDialer.DialWithConn"
},
{
"name": "socksUsernamePassword.Authenticate"
},
{
"name": "stringWriter.WriteString"
},
{
"name": "timeoutHandler.ServeHTTP"
},
{
"name": "timeoutWriter.Write"
},
{
"name": "timeoutWriter.WriteHeader"
},
{
"name": "transportReadFromServerError.Error"
},
{
"name": "unencryptedHTTP2Request.ServeHTTP"
}
]
}
]
}
],
"published": "2026-10-08T23:17:04.760",
"references": [
{
"url": "https://go.dev/cl/847311",
"source": "security@golang.org"
},
{
"url": "https://go.dev/issue/81744",
"source": "security@golang.org"
},
{
"url": "https://groups.google.com/g/golang-announce/c/U2fTuyDJznI",
"source": "security@golang.org"
},
{
"url": "https://pkg.go.dev/vuln/GO-2026-6613",
"source": "security@golang.org"
}
],
"vulnStatus": "Awaiting Analysis",
"weaknesses": [
{
"type": "Secondary",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"description": [
{
"lang": "en",
"value": "CWE-444"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "When an HTTP server handler sends a 2xx response to an HTTP/1 CONNECT request and returns without hijacking the connection, the server improperly continues to read and serve requests from the connection. Since a 2xx response to an HTTP/1 CONNECT converts the connection into a tunnel, the server should not treat the connection as continuing to contain HTTP. The impact of this misbehavior is mostly limited to potential request smuggling, where an intermediate proxy considers the data on the connection to be tunneled and the server considers it to be HTTP."
}
],
"lastModified": "2026-10-09T17:16:50.703",
"sourceIdentifier": "security@golang.org"
}